Silentsoft is an international energy management company, providing solutions to reduce energy consumption in buildings.
In this project, Silentsoft required a corporate message video to be created for use as a centre piece on their web site and loop at trade shows.
The video was created using PowerPoint 2010 since the client requested an ‘open source’ delivery whereby they could, if required, edit the project once it was delivered. This is a very powerful argument for using PowerPoint, but it does have its drawbacks as discussed below.
- PowerPoint 2010 source file with WMV output.
- Professional voice over actress audio narration in US English, French and German.
- Target video length of 3 minutes.
- Input visuals and script from client.
The video below is the final version implemented on the client web sie and is used to explain some of the challenges experienced in using PowerPoint to create video.
PowerPoint 2010* was used almost exclusively to create this video. The only other tool used was an audio editor to post-mix the audio by amplifying it, normalising it and eliminated noise.
This in itself is a powerful illustration of how far PowerPoint has come but some aspects of the project caused a lower than expected productivity rate and there are recommendations made below.
The first thing to note is that ‘audio is King’. While it is possible to change visual sequencing to take more or less time, it’s pretty much impossible to slow down or speed up audio. So the audio time line dictates the length of the video.
Secondly, we recommend that visual animations are synced with audio cues. For example if a word appears in the audio script and on the slide, the use of bookmarks in the audio file can be used to sync the appearance of the visual text. The same is true for visual images which back up the audio point being made. The best way to achieve this is to have the audio divided up into single files for each sentence. While this might seem time consuming, the results are worth the extra effort.
One very important point to note here is that to make the video feel natural, the audio should not break during slide transitions. Since slide transitions take up varying degrees of time (eg: Cut = 0.1 secoonds, Votrex = 4 seconds), if audio is not set to play across these transitions, the resulting video will feel like the auido is ‘chopped’. The way round this is to cut the first audio file from slide N and paste it to slide N-1, setting it to play as the last object on that slide and to play across slides.
There is an unwanted side effect of this technique though. If you are using audio bookmarks, they will not be available to use on slide N in the audio files that span slide transitions, and this can be very painful in a production environment.
Finally, and this is probably the most challenging issue, is that PowerPoint can often present different audio / video synchronisation when playing in a Slide Show compared to the output WMV video file.
While this can often be a limitation of hardware resoruces on the computing platform being used to create the presentation, it is not always the case. This issue can cause adjacent audio files to overlap and audio gaps to be extended, both of which effectively trash the video file it took so long to create.
We have discovered that if you set the presentation to run in a window (Slide Show Settings) and make that window a fraction of your usable display (around 25%) then PowerPoint will play the Slide Show much closer to what it creates in WMV. Then it is just a tedious case of correcting any last sync issues by manually changing animation properties.
Here is a summary of what we think could be improved in PowerPoint 2010+
- Add the ability to ‘Change Audio’ without afecting animation properties in the same way it is currently possible to ‘Change Picture’. Note: it is possible to link to audio files at the point of insertion but this causes extra headaches when the link is removed and bookmarks are deleted.
- Add the ability to change the position of existing audio (and video) bookmarks.
- Add the ability to access bookmarks as animation triggers when media files are played across slides.
- Fix the discrepancies between Slide Show syncing and output video WMV.
*PowerPoint 2010 running on Windows 7 64 bit Ultimate within Parallels VM on a MacBook Air 1.8GHz Intel Core i7 with 4GB memory. VM set to 1.5GB RAM and single CPU use.
Project : Narrated Video for web home page and trade show use
Visual Language : English (US)
Audio Language : English (US)
Time : 03:40
Format : WMV
Video : HD | 1280×720 | 16:9 | 30fps
Audio : Stereo | 320kbps | 44kHz
File Size : 134 MB (106,743,142 bytes)
Embedded Display Size : 576 x 324 (default YouTube size = 560 x 315)
Web Publishing Comments
The code to embed this video has several additional playback control API parameters added to it as per the YouTube developer site to perform the following:
- the video will play automatically when the page loads
- prevent related videos from appearing at the end of playback
- loop the video (also requires the playback parameter)